Configure counter input (CI) channel properties for channels that use a linear encoder to measure linear position.

For more information on encoders and measuring linear displacement, refer to Encoders and Measuring Linear Displacement in the NI-DAQmx Manual.

Property/Section Description
Z Index Mode
Specifies the states at which signal A and signal B must be while signal Z is high for VeriStand to reset the measurement.
Note If signal Z is never high while signal A and signal B are high, you must choose a phase other than A High B High.
  • A High B High—Reset the measurement when signal A and signal B are high.
  • A High B Low—Reset the measurement when signal A is high and signal B is low.
  • A Low B High—Reset the measurement when signal A is low and signal B high.
  • A Low B Low—Reset the measurement when signal A and signal B are low.

When signal Z transitions to high and how long it stays high varies from encoder to encoder. Refer to the documentation for the encoder to determine the timing of signal Z with respect to signal A and signal B.

Decoding

Specifies how to count and interpret the pulses the encoder generates on signal A and signal B. X1, X2, and X4 are valid for quadrature encoders only.

  • 2 Pulse Counting—Increment the count on rising edges of signal A. Decrement the count on rising edges of signal B. If you select this value, the Z Index Mode property is ignored.
  • X1—If signal A leads signal B, count the rising edges of signal A. If signal B leads signal A, count the falling edges of signal A.
  • X2— Count the rising and falling edges of signal A
  • X4—Count the rising and falling edges of signal A and signal B.
Note 2 Pulse Counting is valid only for two-pulse encoders. X2 and X4 decoding are more sensitive to smaller changes in position than X1 encoding, with X4 being the most sensitive. However, more sensitive decoding is more likely to produce erroneous measurements if vibration exists in the encoder or other noise exists in the signals.
Note For device specific information about the default terminals used for counter measurements and generations, refer to Connecting Counter Signals.